WATER-BASED recreational activities have long been recognised as having a positive influence on health and well-being. Since ancient times, bathing in mineral waters has been reputed to cure a variety of illnesses. While there have been few scientific studies of these postulated effects, there is no doubt of the benefits of warm water therapy in pain relief, joint mobility and relaxation.

These days, rising termperatures have seen more and more people taking up recreational activities in and around water, and these are an important part of leisure and tourism around the world. Swimming is recognised as one of the most beneficial forms of exercise and is also an important therapy for rehabilitation after operations such as hip replacements.

Hazards of recreational water use

Water-based recreation, however, can expose people to a variety of health risks, which vary according to the type of water, geographical location and local conditions. These are linked to physical, microbial and chemical hazards.

Physical hazards: drowning and injuries

Drowning is one of the unequivocal dangers of recreational water use. An estimated 400 000 people drown each year. In children, drowning is one of the leading causes of accidental deaths.

Most cases of drowning are the result of drinking alcohol or poor supervision. In seas and rivers, tides and currents are also important hazards and can cause even strong swimmers to drown. In spas and pools, drowning can result from hair or body parts getting caught in inlets and outlets. The clarity of the water can also be a factor. In murky water, people may not see that someone needs help. Overcrowded swimming areas present a similar problem.

Water-based recreational activities can also result in a variety of injuries. Diving or jumping into waters of unknown depth can lead to serious injuries, including spinal injury, which may ultimately result in paraplegia or quadriplegia. Diving into shallow water is the most common cause of spinal injuries. More common, but usually less severe, are injuries arising from discarded glass, cans and needles on beaches or near bathing areas, or injuries from slipping on wet surfaces around pools.

Reducing the risk of drowning and injuries

* Educate children and adults about the risks of water activities, including basic life saving and first-aid techniques

* Supervise children and weak swimmers at all times in or near to swimming areas and water bodies

* Teach children to swim

* Keep beaches clean

* Instal fencing around pools

* Display warnings and water safety instructions

* Improve pool design for safety

Microbial hazards: infections

While the water quality in swimming pools and spas is generally well-monitored, there may be outbreaks of disease due to contamination. The majority of outbreaks are caused by viruses or bacteria linked to faecal contamination. An increasing number of infections are associated with protozoa such as Giardia and Cryptosporidium, which are resistant to commonly used pool disinfectants. Spas present particular risks and require particularly stringent monitoring, as the warm, nutrient-containing, aerobic waters provide an ideal habitat for bacteria to proliferate.

Reducing the risk of infections

* Apply appropriate levels of chlorine or other disinfectants to pools

* Empty, disinfect and clean pools, and filter pool water in cases of accidental faecal release

* Encourage pre-swim showering, toilet use and good hygienic behaviour at pools and spas

* Monitor pH, disinfectant levels and other parameters frequently as part of a routine pool and spa maintenance schedule

* Clean spas and spa filters regularly.

— Excertps taken from the World Health Organisation Guidelines for safe recreational water environments.